I'm developing a site that will need to cache a fair amount of JSON data from an external site, and it seems that some sort of noSQL database is the best option for that. Mongo is my preferred choice, but I'd consider alternatives.

I know Mongo is available on VPS, but I've seen conflicting info about if it's available for shared hosting. I'm figuring to switch the site to a VPS if it actually makes it out of the experimental stage, but don't want to make that commitment just yet.